Blue light-emitting diode technology-operated microscopy is preferable to both short arc mercury lamp-operated microscopy and laser scanning confocal microscopy for direct immunofluorescence images evaluation in routinely diagnosing subepidermal autoimmune blistering diseases.

Direct immunofluorescence (DIF) microscopy still is the gold standard in diagnosing and differentiating subepidermal autoimmune blistering diseases (SABDs) from other bullous diseases. New optical systems were developed that aim to facilitate DIF images evaluation. The aim of the study was to evaluate the usefulness of three fluorescence microscopy systems with different light source for routine diagnostics of SABDs with DIF. In total, perilesional tissue samples for DIF from 34 SABD patients were examined under the three commercial microscopy systems (short arc mercury lamp-operated microscopy-MLM, blue light-emitting diode technology-operated microscopy-bLED and laser scanning confocal microscopy-LSCM) for the detection and pattern analysis of IgA, IgG, IgG1, IgG4, C3 immunoreactants along the dermal-epidermal junction (DEJ) by three independent observers simultaneously. MLM, bLED, and LSCM provided comparable quality of disease-characterizing immunoreactants imaging (number of immunoreactant types detected and patterns of their deposition along DEJ were the same) but screening of slides was quicker using bLED than both LSCM and MLM, as statistical analysis indicated. It is concluded that bLED is an efficient and preferable system for routinely diagnosing SABDs cost-effectively. RESEARCH HIGHLIGHTS: New optical systems were developed that aim to facilitate direct immunofluorescence evaluation. Here, we evaluate the usefulness of three fluorescence microscopy systems with different light source for routine diagnostics concluding that that bLED is an efficient and preferable system.